Adjustable spring-back chair.



E. G. WATKINS.

ADJUSTABLE SPRING BACK CHAIR.

APPLICATION FILED NOV. 1. 1909.

Patented May 30; 1916.

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EDWARD G'. WATKINS, 0F GARDNER, MASSACHUSETTS, ASSIGNOR TO HEYWOOD BROTHERS AND WAKEFIELD COMPANY, OF GARDNER, MASSACHUSETTS, A GOR- PORATION OF NEW JERSEY.

ADJUSTABLE SPRING-BACK CHAIR.

Application filed November 1, 1909.

To all whom it may concern:

Be it known that I, EDWARD G. VVATKiNs, a citizen of the United States, residing at Gardner, in the county of Worcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in Adjustable Spring-Back Chairs, of which the following is a specification, accompanied by drawings forming a part of the same, in which Figure 1 represents a side elevation of a chair embodying my invention. Fig. 2 is a bottom view, with the supporting legs removed. Fig. 3 is a horizontal sectional view on the plane of the broken line 33, Fig. 1. Fig. 4 is a detached view of a flanged plate which is attached to the seat back and is capable of sliding upon the seat back standard. Fig. 5 is a central vertical sectional view through the seat back and the upper end of the seat back standard. Fig. 6 is a detached perspective view of the rocking arm which supports the standard for the seat back, and Fig. 7 is a perspective view of the spider frame.

Similar reference characters refer similar parts in the diiferent figures.

This invention relates particularly to that class of chairs which is adapted to provide a yielding support or rest for the back, for the use of typewriters and others, and it has for its objects to provide for the adjustment of the back rest to secure greater comfort for the occupant, to facilitate the manipulation of the adjustable parts and to increase the strength and rigidity of the supporting framework.

The above objects, among others, are accomplished by the construction and arrangement of parts as hereinafter described and pointed out in the annexed claim.

The different features of construction are illustrated in the accompanying drawings in their preferred form, but are capable of modification without changing the essential character of my invention.

Referring to the chair shown in side view in Fig. 1 of the drawings, 1 denotes the seat, 2 the supporting legs and 3 the back rest vertically adjustable on the standard 4. The seat, in the present instance, is nontiltable, but rotatable and vertically adjustable by being supported upon a screw Specification of Letters Iatent.

Patented May 3Q, 1216. Serial No. 525,662.

threaded spindle 5 which engages a nut 6 supported by the chair legs.

The seat is attached to a pair of angle bars forming spider arms 7, 7 which are bolted, or otherwise secured, to the sides of a spider frame 8, having at its lower end a base plate 9 which is securely attached to the upper end of the screw threaded spindle 5. Pivoted to the lower and rear corners of the spider frame 8 is a two arm lever 10 provided with ears 11, 11 which are pivotally connected with the spider frame and, in the present instance, are cast in a separate piece and attached to the lever 10 by rivets 12. The lower end of the standard 4 is bifurcated to inclose the rear end of the horizontal arm of said lever 10, and is provided with a pivot or bolt 13 which passes transversely through the bifurcated end of the standard 4 and rests in a notch 14 in the lever 10. The bolt 13 serves as a pivotal connection between the said horizontal arm and the standard 4, which allows the latter to be tilted forward or backward to suit the position of the occupant of the chair. Passing through the bifurcated end of the stand ard 4 and also through a slot 15 curved concentrically with the pivot 13 is a bolt 16 carrying a clamping nut 17, which is tightened to clamp the standard 4 upon the said horizontal arm.

The frame 8 is provided with a transverse partition 18, through which passes a bolt 19 having a head 20 loosely held in the vertical arm of said lever 10. The bolt 19 is provided on its outer end with a winged nut 21, between which and the partition 18 is a spiral spring 22. The bolt 19 is placed above the horizontal plane of the pivotal connection between the frame 8 and the lever 10, so that the force of the spring 22 will normally hold the vertical arm of said lever 10 in an elevated position and against the rear edge of the frame 8. Attached tov the rear side of the back rest 3 is a plate 23 having flanges 24 at its edges which inclose the sides of the standard 4.

Near the upper end of the standard 4 is a central longitudinal slot 25 to receive a bolt 26, which passes through a hole 27 in the plate 23 and is provided with a head 28 bearing against the front side of the plate. The bolt 26 carries a nut 29 by which the 7 plate 23 is clamped against the standard 4.

'7 the flanges 24 of the plate 23 inolosing the- The slot 525 permits the back rest 3 to be vertically adjusted on the standard 4, and

WVELICl or backward, in the position of the back rest 3. When the standard 4 has been 7 adjusted and the clamping nut tightened to form a rigid connection between the standard L and the horizontal arm of the lever 10,

a pressure against the back rest 3 will tend V to depress the rear end of said horizontal arm, compressing the spiral spring 22. The described construction formsa yielding support which may be adjusted to suitably counteract the pressure of the occupant by varying the position of the Winged nut 21 on the bolt 19.

By my improved construction all the strains incident to the useof the yielding back support are received by the spider frame 8, which is supported directly above copies ofthis patent may be obtained for the rotating spindle 5. The aXes of the lever 10 and rotating spindle are in contiguous vertical planes Which areincluded within the rigid spider frame 8. The lever is also rigid, so that the yielding movement of the standard 4 is measured by the V tension of the spiral spring 22 and is easily controlled by the adjustment of the Winged nut 21, Which is conveniently located beneath the front portion of the seat.

I claim,

In a chair of the class described, a seat supporting spindle, a seat supporting frame secured upon the upper end of said spindle, and having a vertical Web substantially in the vertical plane of the axis of said spindle, a tWo armed lever pivotally connected to said frame at the rear of said spindle and Web and having one arm extending rearwardly of said Web, a back rest carried by the free end of said arm, the other arm of said lever extending vertically upward in parallel relation to said Web, a bolt connected to the last mentioned arm of said lever, said bolt passing loosely through an aperture in said Web and projecting forwardly of the same, a spring carried by the forwardly projecting portion of said bolt and bearing against said web, and means carriedby the forward end of said bolt for adjusting the tension of said spring.

Dated this twenty eighth day of October 1909. EDWARD G. WATKINS.

Witnesses:

THATOHER B. DUNN, FLORENCE L. MOORE.

five cents each, by addressing the Commissioner of latents, Washington, D. C. 

